This invention relates to piston heads for internal combustion engines of the spark ignition type. The improved piston head has cavities incorporated in the piston head to facilitate the mixture of fuel and air in the combustion chamber.
It is known in the art that good or complete combustion of fuel in an engine depends on thorough mixing of the fuel and air introduced into the combustion chamber as part of the engine combustion process. There are numerous examples of processes and apparatus that control the manner of fuel introduction into an engine. Examples include precombustion chambers, fuel injection methods and other like fuel control means.
Most of the attempts to improve the mixing of fuel and air include modification of the cylinder head or portions of the engine that involve the introduction of the fuel and air into the cylinder of the engine. These alterations may be designed to operate in conjunction with modification to the head of the piston or to the entire piston. All of these designs require extensive modifications to the engine and in particular to the cylinder head and/or piston head.
An example of a modification to a piston or piston head to facilitate fuel distribution for a compression ignition type engine is disclosed in U.S. Pat. No. 3,057,334. In this case a heat plug is mounted in the central portion of the piston. A portion of the plug extends above the head of the piston and has radial grooves formed therein. The fuel issues through a throat from a precombustion chamber to impinge on the plug. The plug grooves serve to disperse the fuel radially outward to promote mixing. This disclosure requires extensive changes to the piston structure as well as a precombustor chamber in the cylinder head.
There are other designs that only modify the piston head to improve fuel entry and exit as well as fuel mixing. U.S. Pat. No. 6,170,454B1 is an example of such a modification. In this instance the contour of the piston head has been modified to affect fuel entry and exhaust flow in the combustion chamber. The structure is designed to circulate the fuel and air mixture circumferentially about the combustion chamber. The contour also serves to con centrate the gas as for example adjacent to the exhaust port during the exhaust cycle. As an additional element to enhance the homogenizing of the fuel and air mixture, shallow dimples are formed in the top or crown of the piston head in multiple cluster configurations. As can be seen there is a need for a simple piston head structure to facilitate thorough mixing of fuel and air to promote efficient combustion. The use of shallow dimples alone will not maximize fuel and air mixing and combustion.
As can be seen, there is a need for a simple method to modify the structure of the internal combustion engine combustion chamber to promote good fuel combustion in the engine.
One object of the present invention is improved combustion of fuel in an engine. Another object is simple modification of engines to increase horsepower and improve fuel usage.